Touch panels have been of wide applications in the fields of household appliances, communications, and electronic information appliances. The common application of the touch panel is an input interface, for example a personal digital assistant (PDA), an electrical appliance, or a game machine. With the integration of the touch panel with a display, a user is allowed to use his or her finger or a stylus to point a control icon shown on a screen in order to enter a desired operation on for example a PDA, an electrical appliance or a game machine. Further, the touch panel is also applied in a public information inquiry system to provide an efficient operation system for the public.
A conventional touch panel comprises a substrate having a surface on which sensing zones are distributed for sensing a signal associated with the touch of a user's finger or stylus to achieve control by touch. The sensing zones are made of transparent conductive membranes, such as ITO, whereby a user may touch the transparent conducive membrane corresponding to a specific location displayed on the display panel to achieve control by touch.
The most commonly known types of touch control techniques include resistive panel, capacitive panel, infrared sensing panel, electromagnetic sensing panel, and sonic sensing panel. The operation of the capacitive touch panel is performed by employing a change in capacitance caused between a transparent electrode and the electrostatics of human body to induce an electrical current based on which the coordinates of a touch location can be identified. The capacitive touch panel is advantageous in light transmittance, hardness, precision, response time, touch cycles, operation temperature and initial force, and is thus most commonly used currently.